Jet combustion fuel



PatentedManZl, 1950 cony-Vacuum Oil Company, corporation of New York emm a No mm...Attracts-Amelie, Serial 100,139,657, I i H y 1 ZCIaims. (Glid -.76)" I This invention has to do with the provision combustion condition ""under-eq a jet ing in jet combustion devices.

The simplest form of jet propulsion mechanism is a tube with one end closed, in which a combustible is burned. The expanding-gases of combustion, issuing from the open end of the tube give rise to a reaction 'efiect which drives the tribe in a direction opposite to that of the emission of gases. The most complicated forms presently proposed consist of the same propulsion or jet tube, plus a compressor to supply air for combustion, plus a gas turbine, which extracts enough energy from the departing gases to drive the compressor. In present commercial forms the compressor and turbine are assembled axially upon a common shaft, spaced far enough apart to permit a number of combustion chambers to be arranged around the shaft between the compressor and turbine, with an exhaust tube extending rearwardly from the turbine.

In essence, the term jet combustion, as now commonly used, and as used in this specification, refers to a method of combustion wherein fuel is continuousl introduced into and continuously burned in a confined space for the purpose of deriving power directly from the hot products of combustion.

In the operation of such devices it has been found that deposits of soot-like character are formed at points in the combustion chamber and in subsequent portions of the apparatus. It will be obvious that in mechanisms wherein a device such as a gas turbine is placed in the combustion gas stream at a point subsequent to the point of combustion, that deposits of this nature can give rise to serious diiliculties, and equally obvious that such deposits should be minimized.

This invention is based upon the discovery that small amounts of thiophene in admixture with standard types of hydrocarbon fuels tend to substantially decrease such deposits. Thiophene is a rather well known organic compound having the formula:

but heretofore it has not been produced in large quantities. It may be produced in commercial quantities by the reaction of butane or butene and sulfur at elevated temperatures. v In order to demonstrate the effectiveness of this additive in the reduction of deposits, test runs were made in a single combustion chamber of the type currently supplied by General Electric under the designation I-16. The fuel flow and air flow were so adjusted as to simulate of hydrocarbon fuel mixtures suitable for burnpropelled-air craft equipped [with 1%16 burner. Comparisons were made between a standard fuel and two fuels each modified [by a difi'erent'con- 'centration of thiophene. Deposit formation was quantitatively evaluated by v'veighing thecombustion chamber liner. 'The table below gives the results of this experimental work;

Table l Deposit Reduction Fuel Weight Deposits Grams Per cent Standard Fuel 0 90.5% Standard Fuel, 0.5% Thiophene.. 6. 7 39. 1 99.0% Standard Fuel, 1.0% Thiophenc.. 5. 7 48. 2

The standard fuel utilized in the above tests was a hydrocarbon distillate fuel having the following characteristics:

Table II Standard fuel:

Gravity, A. P. I 36.5 A. S. T. M. Distillation, F.:

I. B. P 320 5% rec 342 10% rec 350 20% rec 360 30% rec 366 40% rec 3'70 50% rec 380 60% rec 386 10% rec 392 rec 404 rec 422 E. P 468 Per cent rec 98.5 Per cent res 1.5 Per cent loss 0.0 Color, Saybolt +16 Reid vapor press, p. s. l Acid heat, "F 1 Freezing point, F 76 Accel. gum, mg./ ml 2.5 Deposit, mg./200 ml 0.5 Copper dish gum, mg./100 ml Copper dish corrosion Glass dish gum, mg./l00 ml 0.2 Copper strip corrosion, 3 hr. 212 F. Pass Norwood Ibromine No., g. Br./100 g--- 1.0 Vol. per cent aromatics (A. S. T. M.) 12.1 Aniline No., F Sulfur, per cent by weight 0.035

Pour point, F 35 Tag closed flash, F 116 Carbon res., per cent by weight Nil Vis. 100 F., centistokes 1.48 Water tolerance, ml./80 ml 0K T. E. I... mL/gal 0 weight to about 2.0% by weight of thiophene. the 4 preferred amounts being around 1.0% by weight of the fuel.

While the exemplary fuel set forth above has approximately the boiling range characteristics of kerosene, it will be obvious that dependentupon considerations of design. the jet combustion device may be suited to the burning of hydrocarbon distillates of a rather wide variety ranging in boiling ranges from materials having the character of heavy gasolines into materials having the character of rather heavy gas oils and this invention is capable of being utilized with any of the fuels above set forth although its preferred use is with a fuel of approximately kerosene boiling ranges I claim:

1. A liquid fuel capable of being utilized in .jet combustion mechanisms comprising a distillate hydrocarbon petroleum oil boiling within the range of light gasoline to heavy gas oil inclusive and from about 0.1% to about 2.0% by weight of thiophene sufllcient to lessen deposits in the combustion chamber.

2. A liquid fuel capable of being utilized in jet combustion mechanisms comprising a distillate hydrocarbon petroleum oil boiling within the range of light gasoline to heavy gas oil inclusive and from about 0.5% to about 1.0% by weight of thiophene sufllcient to lessen deposits in the combustion chamber.

DONALD P. HEATH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Way Aug. 13, 1946 OTHER REFERENCES Number 

1. A LIQUID FUEL CAPABLE OF BEING UTILIZED IN JET COMBUSTION MECHANISMS COMPRISING A DISTILLATE HYDROCARBON PETROLEUM OIL BOILING WITHIN THE RANGE OF LIGHT GASOLINE TO HEAVY GAS OIL INCLUSIVE AND FROM ABOUT 0.1% TO ABOUT 2.0% BY WEIGHT OF THIOPHENE SUFFICIENT TO LESSEN DEPOSITS IN THE COMBUSTION CHAMBER. 